"So I did my scene this morning for Game Of Thrones," Lightbody wrote. "I looked like this. Can't say much - just it's no pivotal role. Fun!"

Dame Diana Rigg (The Avengers), Mackenzie Crook (The Office), Tara Fitzgerald (Waking the Dead), Tobias Menzies (Casino Royale), Thomas Brodie-Sangster (Doctor Who) and Ellie Kendrick (Being Human) have all signed up for roles in season three of Game of Thrones.